<?php

/**
*分页类
演示
require_once('../libs/classes/page.class.php');
$page=new page(array('total'=>1000,'perpage'=>20));
echo 'mode:1<br>'.$page->show();
echo '<hr>mode:2<br>'.$page->show(2);
echo '<hr>mode:3<br>'.$page->show(3);
echo '<hr>mode:4<br>'.$page->show(4);
echo '<hr>开始AJAX模式:';
$ajaxpage=new page(array('total'=>1000,'perpage'=>20,'ajax'=>'ajax_page','page_name'=>'test'));
echo 'mode:1<br>'.$ajaxpage->show();
*/
class Page {
	/**
	* config ,public
	*/
	var $page_name = "p"; //page标签，用来控制url页。比如说xxx.php?PB_page=2中的PB_page
	var $next_page = '>'; //下一页
	var $pre_page = '<'; //上一页
	var $first_page = 'First'; //首页
	var $last_page = 'Last'; //尾页
	var $pre_bar = '<<'; //上一分页条
	var $next_bar = '>>'; //下一分页条
	var $format_left = '[';
	var $format_right = ']';
	var $is_ajax = false; //是否支持AJAX分页模式

	/**
	* private
	*
	*/
	var $pagebarnum = 10; //控制记录条的个数。
	var $totalpage = 0; //总页数
	var $ajax_action_name = ''; //AJAX动作名
	var $nowindex = 1; //当前页
	var $url = ""; //url地址头
	var $offset = 0;

	/**
	* constructor构造函数
	*
	* @param array $array['total'],$array['perpage'],$array['nowindex'],$array['url'],$array['ajax']...
	*/
	public function Paging($array) {
		if (is_array($array)) {
			if (!array_key_exists('total', $array))
				$this->error(__FUNCTION__, 'need a param of total');
			$total = intval($array['total']);
			$perpage = (array_key_exists('perpage', $array)) ? intval($array['perpage']) : 10;
			$nowindex = (array_key_exists('nowindex', $array)) ? intval($array['nowindex']) : '';
			$this->url = (array_key_exists('url', $array)) ? $array['url'] : '';
		} else {
			$total = $array;
			$perpage = 10;
			$nowindex = '';
			$this->url = '';
		}
		if ((!is_int($total)) || ($total < 0))
			$this->error(__FUNCTION__, $total . ' is not a positive integer!');
		if ((!is_int($perpage)) || ($perpage <= 0))
			$this->error(__FUNCTION__, $perpage . ' is not a positive integer!');
		if (!empty ($array['page_name']))
			$this->set('page_name', $array['page_name']); //设置pagename
		$this->_set_nowindex($nowindex); //设置当前页
		$this->_set_url($this->url); //设置链接地址
		$this->totalpage = ceil($total / $perpage);
		$this->offset = ($this->nowindex - 1) * $perpage;
		if (!empty ($array['ajax']))
			$this->open_ajax($array['ajax']); //打开AJAX模式
	}
	/**
	* 设定类中指定变量名的值，如果改变量不属于这个类，将throw一个exception
	*
	* @param string $var
	* @param string $value
	*/
	function set($var, $value) {
		if (in_array($var, get_object_vars($this)))
			$this-> $var = $value;
		else {
			$this->error(__FUNCTION__, $var . " does not belong to PB_Page!");
		}

	}
	/**
	* 打开倒AJAX模式
	*
	* @param string $action 默认ajax触发的动作。
	*/
	function open_ajax($action) {
		$this->is_ajax = true;
		$this->ajax_action_name = $action;
	}
	/**
	* 获取显示"下一页"的代码
	*
	* @param string $style
	* @return string
	*/
	function next_page($style = '') {
		if ($this->nowindex < $this->totalpage) {
			return $this->_get_link($this->_get_url($this->nowindex + 1), $this->next_page, $style);
		}
		return '<span class="' . $style . '">' . $this->next_page . '</span>';
	}

	/**
	* 获取显示“上一页”的代码
	*
	* @param string $style
	* @return string
	*/
	function pre_page($style = '') {
		if ($this->nowindex > 1) {
			return $this->_get_link($this->_get_url($this->nowindex - 1), $this->pre_page, $style);
		}
		return '<span class="' . $style . '">' . $this->pre_page . '</span>';
	}

	/**
	* 获取显示“首页”的代码
	*
	* @return string
	*/
	function first_page($style = '') {
		if ($this->nowindex == 1) {
			return '<span class="' . $style . '">' . $this->first_page . '</span>';
		}
		return $this->_get_link($this->_get_url(1), $this->first_page, $style);
	}

	/**
	* 获取显示“尾页”的代码
	*
	* @return string
	*/
	function last_page($style = '') {
		if ($this->nowindex == $this->totalpage) {
			return '<span class="' . $style . '">' . $this->last_page . '</span>';
		}
		return $this->_get_link($this->_get_url($this->totalpage), $this->last_page, $style);
	}

	function nowbar($style = '', $nowindex_style = '') {
		$plus = ceil($this->pagebarnum / 2);
		if ($this->pagebarnum - $plus + $this->nowindex > $this->totalpage)
			$plus = ($this->pagebarnum - $this->totalpage + $this->nowindex);
		$begin = $this->nowindex - $plus +1;
		$begin = ($begin >= 1) ? $begin : 1;
		$return = '';
		for ($i = $begin; $i < $begin + $this->pagebarnum; $i++) {
			if ($i <= $this->totalpage) {
				if ($i != $this->nowindex)
					$return .= $this->_get_text($this->_get_link($this->_get_url($i), $i, $style));
				else
					$return .= $this->_get_text('<span class="' .
					$nowindex_style . '">' . $i . '</span>');
			} else {
				break;
			}
			$return .= "\n";
		}
		unset ($begin);
		return $return;
	}
	/**
	* 获取显示跳转按钮的代码
	*
	* @return string
	*/
	function select($url) {
		$this->_set_url(); //设置链接地址
		$return = '<select name="Paging" onchange="document.location.href=\''.$this->url.'\'+this.value">';
		for ($i = 1; $i <= $this->totalpage; $i++) {
			if ($i == $this->nowindex) {
				$return .= '<option value=' . $url . $i . ' selected>' . $i . '</option>';
			} else {
				$return .= '<option value=' . $url . $i . '>' . $i . '</option>';
			}
		}
		unset ($i);
		$return .= '</select>';
		return $return;
	}

	/**
	* 获取mysql 语句中limit需要的值
	*
	* @return string
	*/
	function offset() {
		return $this->offset;
	}

	/**
	* 控制分页显示风格（你可以增加相应的风格）
	*
	* @param int $mode
	* @return string
	*/
	function show($mode = 1, $url = '') {
		switch ($mode) {
			case '1' :
				$this->next_page = '下一页';
				$this->pre_page = '上一页';
				return $this->pre_page() . $this->nowbar() . $this->next_page() . '第' . $this->select($url) . '页';
				break;
			case '2' :
				$this->next_page = '下一页';
				$this->pre_page = '上一页';
				$this->first_page = '首页';
				$this->last_page = '尾页';
				return $this->first_page() . $this->pre_page() . '[第' . $this->nowindex . ' 页]' . $this->next_page() . $this->last_page() . '第 ' . $this->select($url) . '页';
				break;
			case '3' :
				$this->next_page = '下一页';
				$this->pre_page = '上一页';
				$this->first_page = '首页';
				$this->last_page = '尾页';
				return $this->first_page() . $this->pre_page() . $this->next_page() . $this->last_page();
				break;
			case '4' :
				$this->next_page = '下一页';
				$this->pre_page = '上一页';
				return $this->pre_page() . $this->nowbar() . $this->next_page();
				break;
			case '5' :
				return $this->pre_bar() . $this->pre_page() . $this->nowbar() . $this->next_page() . $this->next_bar();
				break;
		}

	}
	/*----------------private function (私有方法)-----------------------------------------------------------*/
	/**
	* 设置url头地址
	* @param: String $url
	* @return boolean
	*/
	function _set_url($url = "") {
		if (!empty ($url)) {
			//手动设置
			$this->url = $url . ((stristr($url, '?')) ? '&' : '?') . $this->page_name . "=";
		} else {
			//自动获取
			if (empty ($_SERVER['QUERY_STRING'])) {
				//不存在QUERY_STRING时
				$this->url = $_SERVER['REQUEST_URI'] . "?" . $this->page_name . "=";
			} else {
				//
				if (stristr($_SERVER['QUERY_STRING'], $this->page_name . '=')) {
					//地址存在页面参数
					$this->url = str_replace($this->page_name . '=' . $this->nowindex, '', $_SERVER['REQUEST_URI']);
					$last = $this->url[strlen($this->url) - 1];
					if ($last == '?' || $last == '&') {
						$this->url .= $this->page_name . "=";
					} else {
						$this->url .= '&' . $this->page_name . "=";
					}
				} else {
					//
					$this->url = $_SERVER['REQUEST_URI'] . '&' . $this->page_name . '=';
				} //end if
			} //end if
		} //end if
	}

	/**
	* 设置当前页面
	*
	*/
	function _set_nowindex($nowindex) {
		if (empty ($nowindex)) {
			//系统获取

			if (isset ($_GET[$this->page_name])) {
				$this->nowindex = intval($_GET[$this->page_name]);
			}
		} else {
			//手动设置
			$this->nowindex = intval($nowindex);
		}
	}

	/**
	* 为指定的页面返回地址值
	*
	* @param int $pageno
	* @return string $url
	*/
	function _get_url($pageno = 1) {
		return $this->url . $pageno;
	}

	/**
	* 获取分页显示文字，比如说默认情况下_get_text('<a href="">1</a>')将返回[<a href="">1</a>]
	*
	* @param String $str
	* @return string $url
	*/
	function _get_text($str) {
		return $this->format_left . $str . $this->format_right;
	}

	/**
	   * 获取链接地址
	*/
	function _get_link($url, $text, $style = '') {
		$style = (empty ($style)) ? '' : 'class="' . $style . '"';
		if ($this->is_ajax) {
			//如果是使用AJAX模式
			return '<a ' . $style . ' href="javascript:' . $this->ajax_action_name . '(\'' . $url . '\')">' . $text . '</a>';
		} else {
			return '<a ' . $style . ' href="' . $url . '">' . $text . '</a>';
		}
	}
	/**
	   * 出错处理方式
	*/
	function error($function, $errormsg) {
		die('Error in file <b>' . __FILE__ . '</b> ,Function <b>' . $function . '()</b> :' . $errormsg);
	}
}


